struct TreeNode {
	int val;
	struct TreeNode* left;
	struct TreeNode* right;
};
struct TreeNode* BinaryTreeFind(struct TreeNode* root, int x) {
	if (root == NULL) return NULL;
	if (root->val == x) return root;
	if (BinaryTreeFind(root->left, x)) return root->left;
	if (BinaryTreeFind(root->right, x)) return root->right;
}